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How to configure the STUSB4500L I2C interface without a dedicated uC/I2C Master?



I am looking into designing a board (sink only) which uses said IC to allow me to use the 15W from the source/PD-compliant source.

From what I understand, the I2C interface attached to a master is used (in addition to other functions) to communicate what Power Delivery Output the IC should demand from the source.

Now, I want to omit having to communicate through a master. Is it possible to for example set a wanted power level via GPIOs? This way I can implement dip switches or something comparably easy to configure a specific Power Delivery Output.

I simply want to be able to make the STUSB4500L negotiate 5V at 3A from the source for me to use it elsewhere on the board.

Thanks in advance,


ST Employee

Hello Gekko

Sink cannot 'force' a source TypeC to deliver 15W.

Sink 'only' checks what source is proposing in term of power and then it takes decision about its application behavior.

There is no 'negotiation' with the source in TypeC.

STUSB4500L offers the possibility to know that's power can be delivered by source on GPIOs (i.e does not need I2C link): see paragraph 2.2.8 of STUSB4500L datasheet.

Best regards